1. Technical Field
The present invention relates to a multi-processor system and a program for causing a computer to execute a controlling method of the multi-processor system, and specifically to a multi-processor system that can smoothly process tasks in parallel and a program for causing a computer to execute a controlling method of the multi-processor system.
2. Related Art
The processor used for a specific device is called a built-in system. Recently, a multi-processor or a multi-thread processor is used for a built-in system. The multi-processor is advantageously used to make the device have few clocks or improve the responsiveness of the device. It is desirable to use a multi-processor in a portable device in particular, as the multi-processor is also advantageous in reducing power consumption.
The determination of whether a newly developed processor operates normally or not takes time and cost. For that reason, in the field of software, if a processor that has been used and proved its good performance can be diverted, it is desirably diverted. When the built-in system is used as a multi-processor, it is requested to divert software of a previously used single processor.
A conventional technique for diverting software of a single processor (function distributed processor) for a multi-processor is described in the patent document 1 for example. The invention of the patent document 1 is for transporting an OS (Operating System) for a function distributed processor based on μITRON (registered trademark) to a multi-processor. The invention of the patent document 1 is for preferentially processing an interruption with higher urgency by accepting an interruption for which a system call is not needed to be issued while a system call for calling an OS is issued in the function distributed processor.    [Patent Document 1] Japanese Patent Laid-Open No. 8-297581
As mentioned above, when a multi-processor is operated only in the function-distributed operating system, it is difficult to cause a plurality of processors to operate in parallel. When a multi-processor is caused to operate only in an OS for SMP (Symmetric Multi Processor) type processor, there is a problem in that quantity of work for a transporting an application that is property of a single processor increases.
For a multi-processor in a built-in device, a plurality of processors (unit processors) with different functions and different features may be provided and a specific task may be allocated to a predetermined unit processor. The task executed only in the specific unit processor (fixed in a unit processor) is called a static task and a task allocated to any unit processor (not fixed in a unit processor) is called a dynamic task. The invention described in the patent document 1, however, simply uses a function-distributed operating system for a multi-processor; thus, the invention does not take into account of treating of a static task of the multi-processor in parallel processing.
The present invention is adapted in view of the abovementioned problems and intends to provide a multi-processor system that can perform parallel processing in consideration of fixing and non-fixing of a unit processor of a task by using property of a program such as an OS of a conventional function-distributed processor, and a program for causing a computer to execute a controlling method of the multi-processor system.